For the Catholic Church, two distinct sources of truth: divine revelation and reason unaided by revelation

But should the failure of the natural-law case against homosexual behavior bother Catholics, who, after all, can also appeal to the Bible’s denunciations of homosexual behavior? Here another aspect of Catholic thought becomes crucial: The church accepts that there are two distinct sources of truth: divine revelation and reason unaided by revelation (for example, the “natural reason” of scientists and philosophers). But it also holds Thomas Aquinas’s view that there can never be a genuine conflict between these two sources. Therefore, any apparent conflict results from our failure to understand what either God or reason is saying.

Most important, there is no assumption, in any given case, that we must resolve the conflict by revising the apparent conclusion of reason. For example, the church (eventually) decided that the scientific claims of Galileo and Darwin were correct and required revisions in teachings based on biblical passages suggesting otherwise.   It is, therefore, an open question whether to accept the reasonable conclusion that homosexual acts need not be immoral and reject the view that this is what the Bible says.

http://opinionator.blogs.nytimes.com/2015/03/12/unraveling-the-church-ban-on-gay-sex/